Process of concentrating calcite



' Patented May 16, 1939 UNITED STATES PATENT OFFICE 3.153,. PROCESS OF OONGENTRA'I'ING carom:

No Drawing l9 as, Serial No.

Original application February 15,

now Patent No.

2,105,807, dated January 18, 1938. Divided and this application January I, 1988, Serial No.

Claims. (01; zoo-m) This application is a division of my (so-pending application Ser. No. 656,887, died February 15, 1933, Patent No. 2,107,807, issued January 18, 1938.

5 The present invention relates in general to a concentration of non-metallic minerals from their ores, and more particularly to an improved process of concentration applicable to ores containing principally calcite and silicious matter.

In accordance with the invention, calcite is concentrated from such ores by the use of a free fatty acid, in conjunction with a substantially insoluble and unsaponiiiable oil. In using these agents, it has been found that no added alkali need be employed for obtaining an eflective and economical separation of calcite from silicious matter. According to the invention, a pulp of the ore to undergo treatment is agitated with a fraction of one per cent. of a free fatty acid and a fraction of one per cent. of a substantially insoluble and unsaponiflable oil, without added agents capable of substantially affecting its pH value, the desired concentrate being subsequently separated by froth flotation or other manner known in the art. By this procedure, omitting the use of added alkali, it has also been found that calcite can in certain'cases be separated from silicious matter even more effectively and more economically than when alkali is added to 30 the ore. If desired, the fatty acid may be added to the ore while carried in at least a part of the substantially insoluble and unsaponiflable oil.

The process of the present invention may also be applied to the separation of phosphate from 35 both calcite and silica, to the separation of fluorspar from bo h calcite and silica, and to the separation of fluorspar'from both barite and silica. However, the claims of this application do not cover this diiierential concentration of non- 0 metallic minerals, which is separately claimed in 11g aforementioned application Serial No. 656,- 8

In order that the best results may be obtained by the process of the present invention, it has 45 been found advisable to limit rather narrowly the size of the ore particles subjected to the concentrating operation, as well as to largely deslime the ore pulp prior to its admixture with the reagents.

50 In preparing the ore for treatment by the process of the present invention, it is ordinarily first subjected to a preliminary grinding operation and is thereafter screened or classified to remove all particles other than those desired. The undersize may then be deslimed and the oversize reground, deslimed, and added to the deslimed undersize; -or the oversize may be reground, added to the undesllmed imdersize, and the whole then deslimed.

An example will now be described giving de- 5 tailed procedures which may be used in carrying the invention into effect.

An ore of calcite and silica was prepared by adding one part Ocala limestone, largely calcite, to three parts tailing from a mill of the Phosphate 10 Recovery Corporation treating Florida pebble phosphate. This ore was sized on a -24-mesh screen, and the oversize ground to the same mesh and added to the undersize. The resulting material was then deslimed by agitation with water 16 and decantation, whereafter it was thickened to -a pulp of about 70% solids. This pulp was agitated' for three minutes in a mixer with 0.53 lb. of crude oleic acid and 2 lbs. of fuel 011, both per ton oi dry material treated. No other agent 20 was added to the pulp, the pH value of which in the mixer was 1.8. Subsequent to the conditioning indicated, the pulp was transferred to a subaeration flotation machine, where it was diluted and irothed for one minute. during which a concentrate of calcite was separated. The results of the test are shown in the following table:

Percentlssay While the procedures given in the foregoing example are flotation procedures, it has been found that in many cases parallel results may be obtained by efl'ecting the concentrating operation on a shaking table, the concentrate comin 40 off at the side of the table, and the tailing at the end of the table.

Having thus described an embodiment of the invention, what is claimed is:

1. A process of concentration which comprises agitating a pulp, nearly free from slimes, of suitably divided particles of an ore containing principally calcite and silicious matter in the presence of a fraction oione per cent. of a free fatty acid and a fraction of one per cent. of a substan- 5o tially insoluble and uusaponifiable oil, without added alkali or other agent capable of substantially affecting its pH value: and-separating a concentrate relatively rich in calcite and relatively poor in silicious matter.

2. A process of concentration which comprises agitating a pulp of suitably divided particles of an ore containing principally calcite and silicious matter in the presence 0! a fraction of one per 5 cent. of a free fatty acid and a fraction of one per cent. 0! a substantially insoluble and unsaponitlable oil, without added alkali or other agent capable 01 substantially ailectingoits pH value; and 'ubiecting the pulp to froth flotation 10 so as to separate a concentrate relatively rich in calcite and relatively poor in siiiclous matter.

3. A process of concentration which comprises agitating a pulp of suitably divided particles of an ore containing principally calcite and silicious u matter in the presence of a fraction of one per value, the iatty acid being carried in at least a part of the oil; and separating a concentrate relatively rich in calcite and relatively poor in silicious matter.

4. aprocessoiconcentraflonwhichccmprises agitating a pulp oi suitably divided particles of an ore containing principally calcite and silicious matter in the presence of a traction of one per cent. of a free fatty acid and a traction of one per cent. of a substantially insoluble and unsaponiflable oil, without added alkali or other agent capable of substantially aflecting its pH value; and separating a concentrate relatively rich in calcite and relatively poor in silicious matter.

5. A process of concentration which comprises agitating a pulp or suitably divided particles of an ore containing principally calcite and silicious matter in the presence or a fraction of one per cent. of tree oleic acid and a traction of one per cent. of fuel oil, without added alkali or other agent capable of substantially aflecting its pH value; and separating a concentrate relatively rich in calcite and relatively poor in silicious matter.

ARTHUR CRAGO.

CERTIF'lICATE OF CORRECTION.

Patent No 2,158,220.

ARTHUR CRAGO.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, first column, 'line 5, for the patent number "2407,80?" read 2,105,807; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed. and sealed this 15th day of June, A. n. 19 9.

(Seal) Henry Van Arsdale Acting Commissioner of Patents.

2. A process of concentration which comprises agitating a pulp of suitably divided particles of an ore containing principally calcite and silicious matter in the presence 0! a fraction of one per 5 cent. of a free fatty acid and a fraction of one per cent. 0! a substantially insoluble and unsaponitlable oil, without added alkali or other agent capable 01 substantially ailectingoits pH value; and 'ubiecting the pulp to froth flotation 10 so as to separate a concentrate relatively rich in calcite and relatively poor in siiiclous matter.

3. A process of concentration which comprises agitating a pulp of suitably divided particles of an ore containing principally calcite and silicious u matter in the presence of a fraction of one per value, the iatty acid being carried in at least a part of the oil; and separating a concentrate relatively rich in calcite and relatively poor in silicious matter.

4. aprocessoiconcentraflonwhichccmprises agitating a pulp oi suitably divided particles of an ore containing principally calcite and silicious matter in the presence of a traction of one per cent. of a free fatty acid and a traction of one per cent. of a substantially insoluble and unsaponiflable oil, without added alkali or other agent capable of substantially aflecting its pH value; and separating a concentrate relatively rich in calcite and relatively poor in silicious matter.

5. A process of concentration which comprises agitating a pulp or suitably divided particles of an ore containing principally calcite and silicious matter in the presence or a fraction of one per cent. of tree oleic acid and a traction of one per cent. of fuel oil, without added alkali or other agent capable of substantially aflecting its pH value; and separating a concentrate relatively rich in calcite and relatively poor in silicious matter.

ARTHUR CRAGO.

CERTIF'lICATE OF CORRECTION.

Patent No 2,158,220.

ARTHUR CRAGO.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, first column, 'line 5, for the patent number "2407,80?" read 2,105,807; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed. and sealed this 15th day of June, A. n. 19 9.

(Seal) Henry Van Arsdale Acting Commissioner of Patents. 

